AvalonLog 0.21.0

.NET 7.0 .NET Framework 4.7.2

dotnet add package AvalonLog --version 0.21.0

NuGet\Install-Package AvalonLog -Version 0.21.0

This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.

<PackageReference Include="AvalonLog" Version="0.21.0" />

For projects that support PackageReference, copy this XML node into the project file to reference the package.

<PackageVersion Include="AvalonLog" Version="0.21.0" />
                    

                            Directory.Packages.props

<PackageReference Include="AvalonLog" />
                    

                            Project file

For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package.

paket add AvalonLog --version 0.21.0

The NuGet Team does not provide support for this client. Please contact its maintainers for support.

#r "nuget: AvalonLog, 0.21.0"

#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.

#:package AvalonLog@0.21.0

#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package.

#addin nuget:?package=AvalonLog&version=0.21.0
                    

                            Install as a Cake Addin

#tool nuget:?package=AvalonLog&version=0.21.0
                    

                            Install as a Cake Tool

The NuGet Team does not provide support for this client. Please contact its maintainers for support.

Logo

AvalonLog

code size

AvalonLog is a fast and thread-safe WPF text log viewer for colored text. Including F# printf formatting. Based on AvalonEditB. Works on .NET Framework 4.7.2 and .NET 7.0+

Thread-safe means that it can be called from any thread. A print call never waits for the UI thread.

Fast means

it buffers repeated print calls and updates the view at most 20 times per second (see PrintInterval). see source
Avalonedit is fast, the view is virtualized. It can easily handle thousands of lines.

Use with F#

Here an short example for F# interactive in .NET Framework. (for net5 or higher you would have to use it in a project)

#r "PresentationCore"
#r "PresentationFramework"
#r "WindowsBase"

#r "nuget: AvalonLog"

open System.Windows

let log = new AvalonLog.AvalonLog() // The main class wrapping an Avalonedit TextEditor as append only log.

// create some printing functions by partial application:
let red   = log.printfColor 255 0 0  // without newline
let blue  = log.printfnColor 0 0 255 // with newline
let green = log.printfnColor 0 155 0 // with newline

// print to log using F# printf formatting
red   "Hello, "
blue  "World!"
red   "The answer"
green " is %d." (40 + 2)

Application().Run(Window(Content=log))  // show WPF window

this will produce

WPF window

Use in C#

public void AppendWithBrush(SolidColorBrush br, string s)

and similar functions on the AvalonLog instance.

When used from C# add a reference to FSharp.Core 6.0.7 or higher.

Full API Documentation

goswinr.github.io/AvalonLog

Download

AvalonLog is available as NuGet package.

How to build

Just run dotnet build

How to test

Run dotnet test. The tests in Tests run on .NET Framework 4.7.2 and .NET 8, they need Windows (WPF).

Changelog

see CHANGELOG.md

License

MIT

Logo by LovePik

Product	Compatible and additional computed target framework versions.
.NET	net7.0-windows7.0 is compatible. net8.0-windows was computed. net9.0-windows was computed. net10.0-windows was computed.
.NET Framework	net472 is compatible. net48 was computed. net481 was computed.

Compatible target framework(s)

Included target framework(s) (in package)

Learn more about Target Frameworks and .NET Standard.

.NETFramework 4.7.2
- AvalonEditB (>= 2.5.0)
net7.0-windows7.0
- AvalonEditB (>= 2.5.0)

NuGet packages (1)

Showing the top 1 NuGet packages that depend on AvalonLog:

Package	Downloads
Fesh A hostable fsharp scripting editor for Windows based on Avalonedit	25.8K

GitHub repositories

This package is not used by any popular GitHub repositories.

Version	Downloads	Last Updated
0.21.0	65	10/10/2026
0.20.0	4,923	3/19/2025
0.19.0	411	3/18/2025
0.18.0	629	2/15/2025
0.17.0	1,051	11/18/2024
0.16.0	355	11/6/2024
0.15.8	311	11/3/2024
0.15.0	282	11/3/2024
0.14.0	369	9/11/2024
0.13.0	329	6/10/2024
0.12.0	481	10/29/2023
0.11.0	331	9/10/2023
0.10.0	344	7/27/2023
0.9.3	346	5/29/2023
0.9.2	457	5/29/2023
0.9.1	381	4/29/2023
0.9.0	381	4/23/2023
0.8.3	529	1/8/2023
0.8.2	501	12/17/2022
0.8.1	527	12/17/2022

### Added

- Tests (xunit), run them with `dotnet test`
- `SelectedTextHighlighter.ClearHighlight()` to remove the highlights of all occurrences of the selected text

### Changed

- Highlights of all occurrences of the selected text now stay until Escape is pressed in the log (after closing the search panel, if open) or a new text is selected
- Selected text is never highlighted by the `SelectedTextHighlighter`, also within multi-line and rectangular selections, because the selection has its own highlighting
- `OnHighlightChanged` is also raised when the text changes, to keep the count up to date while a highlight is shown
- Update AvalonEditB to 2.5.0
- New text only scrolls the view to the end if it was already at the end. So you can scroll up and read while text is printed. Scrolling back to the end resumes following.
- Text printed with the default color (`Append`, `AppendLine`) now always uses the current `Foreground` of the editor, so it follows theme changes. Before, it was a copy of the Foreground at creation (or at the last `Clear()`).
- Printing never blocks the printing thread. One shared timer posts the text to the UI thread, at most every `PrintInterval` (50 ms). A single printfn now updates the screen once instead of twice. Printing 200k lines via `Console.Out` is about 10x faster.

### Fixed

- `SelectedTextHighlighter`: the background count search is delayed by 100 ms and only raises `OnHighlightChanged` if no newer search or clearing happened, so results can no longer arrive out of order or after `OnHighlightCleared`. Disabling via `IsEnabled` no longer raises `OnHighlightCleared` twice. Setting `ColorHighlighting` redraws immediately
- TextWriter: `Write(char)`, `Write(char[])`, `Write(ReadOnlySpan<char>)` and `Write(StringBuilder)` were silently dropped
- Printing a null string threw a NullReferenceException, now it prints nothing
- The undo stack kept a copy of all printed text, it is disabled now
- An exception while sending text to the UI thread from a background timer could terminate the host process. Printing also stops by itself once the UI Dispatcher shuts down
- When `MaximumCharacterAllowance` was reached by several threads at once, the stop message could get printed more than once. A single print that is longer than the remaining allowance now gets cut off at the maximum, so it cannot freeze the UI
- Printing with a color from two threads at once could print a line in the other thread's color. Printing with the same RGB color no longer creates a new brush each time
- `AppendWithBrush`, `AppendLineWithBrush`, `printfBrush` and `printfnBrush` did not freeze the brush, so an unfrozen brush created on a worker thread crashed the rendering on the UI thread
- On .NET Framework the editor and the TextWriter reported the ANSI code page as encoding, now UTF-8 (without BOM), like on .NET Core
- Selecting text crashed the process when there is no WPF `Application` object (e.g. in a plugin of a non WPF host). The selection highlighter now uses the Dispatcher of the editor
- Clearing the log while another thread was printing made that thread's text lose its color
- A color change in the middle of a line split the rest of the line into one element per character, making its redraw up to 100x slower